Using this innovative approach, it is possible to achieve an efficient heat transfer across a large electrical potential difference with an entirely passive device. The fluid used for convection absorbs the heat by conduction and then moves away carrying the heat within it. Robust heat exchanger with 6 high quality and high performance heat pipes choice of 1 or 2 12 volt fans see tables 2 and 3 for fan and exchanger specifications see figures 1 and 2 for mounting pattern and other details 3100a400 heat pipe. The notebook computer is the most popular heat pipe application for cpu. There are several limits that govern heat pipe theory, however in terrestrial applications the capillary limit is the most limiting factor. The real production process of these tremendously important parts is the topic of this first part of our behindthe. Copperwater copperwater heat pipes are simple and reliable that provide high performance operation thats applicable to a variety of applications. Heat pipes do not actually dissipate the heat and are therefore incorporated into many different types of heat sinks as helpers. Examples of thermal solutions using custom heat pipes can be found on this page.
However, in an actual application when a heat pipe is soldered or epoxied to the base of a heat sink, the effective thermal conductivity of the heat pipe may be. A heat pipe is a heattransfer device that combines the principles of both thermal conductivity. This latest edition has been thoroughly revised, updated and expanded to give an indepth coverage of the new developments in the field. The calculations of the various variants of the wick structure of heat pipe and working. This article is intended to offer design guidance when using heat pipes for the most prevalent types of electronics applications. Een heat pipe is een transportmechanisme dat grote hoeveelheden warmte kan verplaatsen. A heatpipe is a sealed copper tube that is under vacuum, and can transfer heat rapidly away from the source. The most efficient and costeffective way to implement this would be with a single, 95mmwide pipe, perhaps secured between metal plates for flatness and rigidity id have the top plate curve away at the edges to avoid sharp bends in the pipe, long enough to extend to the case side panel above the cpu on both sides, and attaching the pipe. A quantitative engineering theory for the design and performance analysis of heat pipes is given. Mathematical model for heat transfer limitations of heat pipe. Cooling fin or water heatpi e thermal couple thermal couple t2,t3,t4 adiabatic heat block power supply thermal couple tl power supply.
Thermacores answer was in the design of a powder metal wick that transfers cpu heat from a tightly confined spot to an area near available air flow. These low profile heat pipes are designed to transfer heat with minimal temperature difference or spread the heat across a surface in electronics cooling applications. Heat pipes, 6th edition, takes a highly practical approach to the design and selection of heat pipes, making it an essential guide for practicing engineers and an ideal text for postgraduate students. Heat pipes heat transport limit for proper heat pipe operation, the total pressure drop must not exceed its capillary pressure head. Users manual for heat pipe fluid properties program. In the short heat pipe extreme 34 length, this effect is nearly zero, so please consult with wakefieldvette engineers to find the right solution for your application.
It emphasizes the physical aspects of heat pipe behavior and develops design formulas on the basis of mathematical models and empirical observation. The embedded heat pipe design as shown in figure 2 is a reusable alternative to traditional consumable ablative heat shield employed on hypersonic leading edge applications. Heat pipe design and technology modern applications for. Details as to considerations of pipe systems are given in. The crosssectional area of a heat pipe is the direct function of both the sonic and entrainment limit of the heat pipe. A heat pipe is a heat transfer device that combines the principles of both thermal conductivity and phase transition to effectively transfer heat between two solid interfaces. Calculate accurate savings predictions thanks to flexible hours of operation input. This method has been used in the aerospace industry for about thr ee decades for supporting systemlevel design analysis. For a given heat pipe design, the maximum heat pipe. Pipeline engineering fluid flow mechanical energy balance. Thermal characteristic of double wall thermosyphon was modelled using fem code. Properly fabricated copperwater heat pipes have been operated for over twenty years without maintenance. A computer program for designing and predicting the performance of the heat pipe systems was developed.
Mathematical modeling, numerical simulation and statistical optimization of heat pipe design camcos team. Etst50 axe, a highperformance sideflow cpu cooler with 5 x o6mm heat pipes, features a 12cm dfrtmdust free rotation technology fan and patented pressure differential flow pdf design, offering users an outstanding cooling solution with powerful 250w tdp support. Heat sink design guide when it comes to electronics that dissipate power in the form of heat during normal operation, it is often necessary to manage this heat, to ensure the components dont exceed their maximum allowable temperatures. In the search for a more efficient a heat pipe design, thermal. Heat sink design goals may vary, but in this report, optimization of the vertical heat sink is the main objective. Many factors have to be considered in choosing a heat pipe for a specific application. In this chapter, a cpu thermal design power tdp, cooling methods of electronic equipments, heat pipe theory and operation, heat pipes components, such. Design considerations when using heat pipes electronics cooling. In this chapter, a cpu thermal design power tdp, cooling methods of electronic equipments, heat pipe. Project description by means of knowledge about the theory of heat pipes, one is now able to carry out a basic calculation of a heat pipe.
Spc heat pipes for dehumidification and heat recovery technology technology 4 basic operation this diagram shows the basic structure of a heat pipe and identifies the major steps in the heat pipe process. Journals frontiers in heat pipes fhp thermalfluids. A loop heat pipe with coherent pores integrated to the heat source is considered as a calculation model in this paperfig. Design and technology of heat pipes for cooling and heat. During its trip through the pipe, heat is absorbed by the adjoining hopefully large heatsink, where it is dissipated through the fins. In this chapter, a cpu thermal design power tdp, cooling methods of electronic equipments, heat pipe theory and operation, heat pipes components, such as the wall material, the wick structure. Heat pipe and phase change heat transfer technologies for. Heat is absorbed from the incoming warm air stream in the evaporator section, boiling the refrigerant. Engineers are constantly working to improve electronics. Proper selection and design of the pipe container, working fluid, and wick structure. Design a controllable wrap around heat pipe design strategy doas unit neutral air dehumidification heat pipe dhp economic analysis. This effect is similar to placing a paper towel in coffee, and watching the fluid rise up the paper towel. For example, choice of the wick and case material eliminates many candidate working fluids often including water due to. Due to the numerous advantages of the heat pipe in electronic cooling, this chapter.
Flanges can be added on the outer surface for easy integration with instruments or radiators the flange is an integral part of the extrusion. A technology that is often overlooked as a design option are heat pipes. Heat pipes a novel cooling principle for generator. The heat pipe has many applications, particularly in electronics and related area such as pc, laptop, display, artificial satellite, and telecommunication modules. This new edition has been revised to include new information on the underlying theory of heat pipes and heat transfer, and features fully updated applications, new data sections, and.
The heat pipe utilizes phase change heat transfer inside enveloped structures, where the working fluid evaporates in heated zone, and vapor. Learn how to use step by step with tutorial videos. The thermal design and simulation method of a rack with a large scale flat plate pulsating heat pipe for inner air cooling was studied in this paper. Peter kew first became involved in heat pipes in the late 1970s as a research officer with international research and development working on a range of heat transfer and energy conservation projects, including heat pipe development which was then led by david reay. Customized heat pipes can transfer heat from the source to almost anywhere that the design requires. Consequently, heat pipes can be a viable and promising solution for this challenge. This allows the use of high volume, lower cost heat pipes in a heat sink design. Advanced cooling technologies yale eastman currently a director of act, a few years later describes the theory and history of the heat pipe technology in an article published in scientific american, may 1968. Design and technology of heat pipes for cooling and heat exchange. Generate performance reports, psychrometrics and dimensional drawings. However, the operational temperature of the heat pipe also affects the sonic limit of the heat pipe. Access cloudbased heat pipe selection software from anywhere, anytime. For example, highend cpu servers are traditionally cooled via forced air. Mvk160 heat and mass transfer may 7, 2012, lund, sweden heat pipe, selection of working.
Multiple heat pipes, embedded heat pipes, tower heat pipes, highpower heat pipes, vapor chambers and loop heat pipes all offer the flexibility to help design efficient cooling and longer life into any system. This book provides a practical study of modern heat pipe engineering, discussing how it can be optimized for use on a wider scale. When used outside of its design heat range, the heat pipes thermal conductivity is. Design and technology of heat pipes for cooling and heat exchange crc press book this book describes the characteristics of heat pipes under steadystate and transient operating conditions. Heat pipe 1piece vapor chamber 2piece vapor chamber 20 heat pipes bend radius 3x diameter of heat pipe. Jan 22, 2015 heatpipe design consists of a ceramic shell and an inner metallic tube. Heat pipe operating principles pressure drops operating temperature functional types of heat pipes heat pipe operating characteristics heat pipe design and selection design considerations mostly for vendors selecting heat pipes as part of thermal control system and. In this chapter, a cpu thermal design power tdp, cooling methods of electronic. Numerical modeling, analysis, and experimental simulation of heat pipes have also significantly progressed due to a. Heat pipes are a transport mechanism to move heat from the hot source to an area where the heat can be dissipated. Evaporator temperature of heat pipe, measurement on heat pipe top side. Simulated cpu to heat the heating end of a heat pipe. Ideal when heat needs to be moved more than 3050mm remote fin stacks heat exchangers are a perfect example as with any heat pipe heat sink design, size the heat pipe with an additional 25% thermal headroom if youre interested in spreading heat to reduce hot spot andor attach to a local heat exchanger.
As electronic design allows higher throughputin smaller packages, dissipating the heat. Investigation on thermal design of a rack with the pulsating. Pdf heat pipes for computer cooling applications researchgate. The perkins tube design closest to the present heat pipe was patented by jacob perkins 1836. A design goal of an ohp is to minimize all the resistances in equation 2 in order to. Figure 7 shows a flat pipe design, they can be used as heat spreaders.
As with any design process, many of the decisions that must be taken are interrelated and the process is iterative. In this chapter, a cpu thermal design power tdp, cooling methods of electronic equipments, heat pipe theory and operation, heat pipes components. Heat pipe operation introduction all electronic components, from microprocessors to high end powerconverters, generate heat and rejection of this heat is necessary for theiroptimum and reliable operation. The envelope is evacuated, water is added, and then the heat pipe is sealed. The heat pipe is a wellknown cooling module for advanced electronic devices. Design and manufacture of ceramic heat pipes for high. This type of cooling design works in the same way as heat pipes, but are spread out over a larger area. A heat pipe is a heattransfer device that combines the principles of both thermal conductivity and phase transition to effectively transfer heat between two solid interfaces. Figure 2 compares the heat transport for heat pipes with different diameters. Haringx 10 modeled the bellow as the combination of annular plates connected by elastic cylinders and derived. Contact our experienced engineering team to learn how to recover and save energy with heat pipe technology. Pdf this book provides a practical study of modern heat pipe engineering, discussing how it can be optimized for use on a wider scale. Allows direct contact with heat source 1piece vapor chamber 10mm bend radius along. The high thermal conductivity enables a heat pipe to transfer, and dissipate heat to a more convenient location through a capillary action.
This may help reducing the weight penalty of the thermal protection system for the launch vehicle. The obtained results are expected to lead to guidelines that will allow the design of the thermal management system with optimized heat pipe cooling system for cpu cooling system with maximum cooling capacity. Pdf design guide and heat pipe selection researchgate. The heat pipe temperature reaches the water temperature in about 25 seconds, while the copper rod reaches just 30c after 200 seconds. The total heat load a heat pipe can carry is a function of total length, evaporator and condenser length, diameter, and orientation with respect to gravity. Loop heat pipe with coherent porous wick since the porous material used for current heat pipes is usually stochastic structure, it is hard to apply analytical or numerical methods for design optimization. In this chapter, a cpu thermal design power tdp, cooling methods of electronic equipments, heat pipe theory and operation, heat pipes components, such as the. Once the correct heat pipe s have been identified the next step is integration into the heat sink.
When selecting the diameter and length of heat pipe it is important to consider the orientation with respect to gravity. Heat pipes are initially manufactured in round shapes, but can be customized through a series of bending and flattening processes to form 2d or 3d shapes. A detailed overview of heat pipes is presented in this paper, including a historical perspective, principles of operations, types of heat pipes, heat pipe performance characteristics, heat pipe limitations, heat pipe frozen startup and shutdown, heat pipe analysis and simulations, and various applications of heat pipes. Pipe systems have always special characterstics and must be closely inspected for the choice of the appropriate pump. Ats engineering ebook advanced thermal solutions, inc. Heat pipes hardware m t l l i t b ith th i fmetal aluminum tube with grooves on the inner surface cold t ild extrusion grooves are filled with the working fluid water, ammonia, propylene, etc. Heat pipes for computer cooling applications intechopen. Adiabatic temperature of heat pipe, measurement on heat pipe top side. The heat pipe with porous media gives the cpu temperature lower than without porous media. When heat pipes are used to move heat vs spread heat this is a twostep process. A heat pipe is a selfcontained structure which achieves very high thermal conductance by means of twophase fluid flow with capillary circulation. The drawbacks of an active cooling system can thus be fully avoided. For a given heat pipe design, the maximum heat pipe power is a function of length, adverse gravitational heat evaporator located above the condenser, and. One of the ways they have utilized the heat pipe design and theory, was to create thin flat heat pipe systems also known as heat spreaders.
When the heat source is much smaller than the heat sink base, a flat. Thermomechanical design and characterization of flexible. Heat transfer from the heat sink consists of radiation and convection from both the intrafin passages and the unshielded surfaces of two outer fins. Beginning with a definition of the problem, including the temperature. Heat pipes are an extremely effective method of reducing hot spot temperatures and increasing allowable power in a system by moving heat to an external sink or spreading heat along a surface. At the hot interface of a heat pipe a liquid in contact with a thermally conductive solid surface turns into a vapor by absorbing heat from that surface. A comprehensive, uptodate coverage of the theory, design and manufacture of heat pipes and their applications. Pdf with its unique ability to transfer heat over large distances with minimal. Heat pipe engineering ebook advanced thermal solutions. Heat pipe manufacturers generally provide data sheets. Laser brazing technology is suitable to seal ceramic heatpipes. Heat pipe design handbook, volume 1 internet archive. Such a demand necessitates researchers to explore efficient approaches for central processing unit cpu cooling. Pdf heat pipes and its closed twophase thermosyphons are highly efficient.
Although it is widely used by many industries it is sometimes considered by the uninitiated to be a device that is difficult to design into a system. In the research, the inside and outside air of the rack was separated, and heat exchange was carried out through the plate pulsating heat pipe. Acts expertise with heat pipe technology can find a thermal solution for your industry. The thermacore heat pipe technology permits a notebook computer to be operated in any position, even upside down, without loss of performance.
Condenser temperature, sensor is embedded between hp and condenser section of heat pipe. Mathematical modeling, numerical simulation and statistical. Heat pipe design guidance for heat sink integration. How to model a heat pipe a brief explanation is provided of a networkbased method that is suitable for modeling constant conductance heat pipes cchps, also called fixed conductance heat pipes or fchps and vapor chamber fins. Heat pipes are used to transfer heat with minimal temperature difference from the heat source evaporator to the heat sink condenser as well as to spread the heat across a surface. Hence, other than thermal design of the heat pipe, mechanical design of the. Thermal management system of cpu cooling with a novel.